Combine chilis, fish sauce, lime juice, and sugar, stir well, set aside. Rub the 4 cloves of garlic into the fillets along with salt and white pepper, allow to marinate for 25 minutes. Sprinkle fish with corn starch, saute fish in oil for 5 minutes per side, until golden brown. Add garlic, saute 1 minute. Add fish sauce and cilantro, saute 1 minute, serve over rice, covered with chili lime sauce.